The invention relates generally to a plate used for bone stabilization and more particularly to plates having means to adjust the spacing between points of attachment to the bone or bones along the longitudinal axis. In a further embodiment the adjustment means is designed to accordion in a way which maintains the longitudinal alignment of the points of attachment.
Orthopaedic implants have long been used for the stabilization of bones. For example, plates have been used in conjunction with screws on long bones, and screws and hooks have been used in conjunction with rod seats and rods in the spine as a method of treating traumatic injuries as well as to correct severe misalignments such as scoliosis.
While plates have the advantage of simplifying assembly during surgical implantation, traditional applications of plates have not been as flexible as other means of fixation such as rods and anchors due to the fact that plates do not allow for longitudinal variation of the spacings at the fixation site. For some sites or bone conditions, the exact location for fixation may be limited and in such instances it is extremely advantageous to be able to readily adapt to the site by reshaping a plate and also to be able to vary the angle of entry of the anchoring screw(s) or other anchoring means.
It is therefore an object of the present invention to provide a fixation or stabilization plate for surgical implantation in humans or other animals wherein the location of the anchoring sites along the longitudinal axis can be varied by increasing or decreasing the distance.
It is a further object of the invention to provide a bone plate in which the alignment of the fixation sites along the longitudinal site can be varied.
It is a further object of the invention to provide a plate having fixation sites which enable variation in the angle of entry of an anchor such as a bone screw.
It is a further object of the invention to provide a plate having variable screw spacing substantially along a single axis.